Fluid Mechanics1

Question 1

How is a fluid defined?

Answer 1

A fluid is a substance, that continually deforms (flows)under applied stress.
fluid is often used as a synonym for ‘liquid’ ( false air is also a fluid)

Question 2

How is Density defined (including physical symbols)

Answer 2

the density of a material is defined as its mass per unit volume- ρ (kg/m3) mass/volume

Question 3

how is Viscosity defined?

Answer 3

Viscosity can be defined as the measure of the resistance of a fluid which is being deformed by either shear( perpendicular) or tensile(tangential) stress
-μ (Pa.s)

for fluids, viscosity can be thought of as the ‘thickness’ of the fluid

Question 4

what is tensile stress?

Answer 4

stress applied perpendicular

Question 5

what is shear stress?

Answer 5

stress applied tangential

Question 6

How is pressure defined?

Answer 6

pressure is the force over an area applied to an object in a direction perpendicular to the surface

Question 7

what is the gauge pressure?

Answer 7

gauge pressure is the pressure relative to the atmospheric or ambient pressure

Question 8

Pressure can be measured in?

Answer 8

– N/m2 = Pascal (Pa)
– atmospheres (atm)
– Pounds per Square Inch (PSI)
– Millimeters of Mercury (mmHg)

Question 9

Pressure at ambient (atmospheric) conditions?

Answer 9

1 atm
101325 Pa or 101.325 kPa
14.7PSI
760mmHg

Question 10

how to calculate the pressure in a certain point in a liquid?`

Answer 10

p2=patm+ρgH

pressure in point in liquid= atmospheric pressure+ density of liquidgravityheight of liquid